As a solid-state imaging device, those using the CMOS technique are known, and among these, a passive pixel sensor (PPS) type solid-state imaging device is known (see Patent Document 1). The PPS type solid-state imaging device has a structure where PPS type pixel portions including photodiodes for generating charges of amounts according to incident light intensities are two-dimensionally arrayed in M rows and N columns. In each pixel portion, charges generated in the photodiode in response to light incidence are accumulated in a capacitive element of an integrating circuit, and a voltage value according to the accumulated charge amount is output.
In general, an output terminal of each of the M pixel portions belonging to each column is connected to an input terminal of an integrating circuit provided corresponding to the column via a reading-out wiring provided corresponding to the column. And, in order from the first row to the M-th row, a charge generated in the photodiode of the pixel portion is inputted to a corresponding integrating circuit through a corresponding reading-out wiring, and a voltage value according to the charge amount is outputted from the integrating circuit.
Moreover, each of the N pixel portions belonging to each row is connected to a controlling section via a row selecting wiring provided corresponding to the row. In accordance with a row selecting controlling signal transmitted from the controlling section via the row selecting wiring, each pixel portion outputs a charge generated in the photodiode to the reading-out wiring.
The PPS type solid-state imaging device is used for various purposes. For example, the PPS type solid-state imaging device is used in combination with a scintillator panel as an X-ray flat panel also for medical purposes and industrial purposes. Further, the PPS type solid-state imaging device is also used, specifically, in an X-ray CT apparatus, a microfocus X-ray inspection system, etc. The solid-state imaging device to be used for these purposes has a large-area photodetecting section in which M×N pixel portions are two-dimensionally arrayed, and the photodetecting section may be integrated on a semiconductor substrate having a size with sides more than 10 centimeters in length. Therefore, only one solid-state imaging device may be produced from one semiconductor wafer.
Patent Document 1: Japanese Laid-Open Patent Application No. 2006-234557